I really spent several hours with NFSv4 problems due to a
non-invalidated netgroup cache on reboot. Seemingly, the nscd cache of
nscd in Debian squeeze is incompatible with the nscd cache of nscd in
Debian jessie. So checking if a host is in a given netgroup always
fails if nscd is running.

Steps to reproduce (you don't wanna do this, as it takes hours):
Install a Debian Edu squeeze server
Upgrade it to Debian (Edu) jessie
Add a new test-host to the workstation-hosts netgroup (in LDAP)
Check if the test-host is in the netgroup:

As this issue will be bugging people upgrading a Debian Edu main
server from squeeze to wheezy/jessie, the Debian Edu team will highly
appreciate it to such a change as proposed above enter Debian jessie.